Iaijutsu & Frenzied
Due to the fact that only a certain percentage of the time does the attack hit the max amount of times, each upgrade essentially is receiving LESS then the original 5 dmg power increase that other skills enjoy.
These multiple attacks are a gamble for high burst and high risk.
They have the potential to deal tremendous damage when hit at full, and also the potential to next to nothing at all.
//
28 x 5 = 140
under the assumption that every level of hits has a equal chance (20% chance of hitting once or twice, or thrice etc etc.)
On average frenzied attack hits 3 times.
28 x 3 = 84
now lets compare this with the upgrade.
29 x 3 = 87
As you can see, this upgrade system of using the MAXIMUM HITS to gauge the upgrade value is flawed and punishes the idea of the skill which is gambling for higher damage.
I suggest that the damage added per upgrade be increased to match the average increase with those of other skills.
in short, make frenzied attack gain +2 dmg per upgrade